Reticle construction



July 30, 1968 R. s. THOMAS RETICLE CONSTRUCTION Filed March 17, 1966NVENTOR EH QQ 54 50 @g 'zflguo 5e 1 1205521- S THOMAS United StatesPatent 3,394,461 RETICLE CONSTRUCTION Robert S. Thomas, Perry, W. Va.26844 Filed Mar. 17, 1966, Ser. No. 541,445 3 Claims. (Cl. 33-50)ABSTRACT OF THE DISCLOSURE A reticle having a cored wire wherein thecover for the core is reduced or the core exposed at a central portionthus to create the effect of a tapered reticle.

This invention pertains to telescopic sighting devices, and morespecifically, to reticle constructions employed in such devices. It isthe general objective of this invention to provide new and novelreticles of the tapered variety and improved means for the formation ofsuch reticles.

Recent developments in the art of construction of telescopic sightingdevices have been concerned with devices of variable magnification.Particularly, in the field of firearm sighting devices, it has becomedesirable to incorporate reticles which include cross strands, posts, orthe like which are tapered such that they are of minimum dimension attheir intersections or substantially at the center of the device at thefocal plane thereof. Such tapering of the crossed devices is known tothe art, and is disclosed, for example, in a prior US. patent toBenford, No. 2,800,718, among others. A primary object of the presentinvention relates to the formation of tapered reticles of improved form,these reticles being formed by an improved process which is inexpensive,requires no special tools or equipment, and which provides a reticlewherein the crossed strands or posts may be reduced to minimumdimension, and specifically shaped.

Other and further objects and advantages of the invention will becomeapparent to those skilled in the art from a consideration of thefollowing specification when read in conjunction with the annexeddrawing, in which:

FIGURE 1 is a perspective view showing a first form of reticle of thisinvention at an intermediate stage of manufacture;

FIGURE 2 shows the reticle of FIGURE 1 at a further intermediatemanufacturing level;

FIGURE 3 is an enlarged, central view of the inner section of two crossstrands of the material of fabrication employed in the formation of onetype of reticle hereof;

FIGURE 4 is a further enlarged sectional view on the line 44 of FIGURE3;

FIGURE 5 shows the FIGURE 3 material following one type of processinghereof;

FIGURE '6 is a sectional view on the line 6-6 of FIGURE 5, looking inthe direction of the arrows;

FIGURE 7 is a view similar to FIGURE 5, showing a finished cross strandarrangement following a second type of treatment;

FIGURE 8 shows a modification involving a different type of material;

FIGURE 9 is another modification embodying the material employed in theform of the invention shown in FIGURE 8; and

FIGURE 10 discloses still another form.

In the formation of telescope reticles, it is customary to connect oneor more strands or the like to a ring element, or to inscribe indicia ona substantially transparent disc. Materials employed for the strands andthe like include extremely fine diameter wires, and similar materials.It is recognized as desirable, particularly in the case of telescopicfirearm sighting devices, that the strand 3,394,461 Patented July 30,1968 ice be of minimum dimension at its center, or at the intersectionof plural strands where more than one is employed.

In FIGURES 1 and 2 of the drawing a conventional reticle retaining ring20 of annular form is shown, having a peripheral outer edge 22, and sidesurfaces 24. In the first forms of the invention (FIGURES 3 through 7)cross strands 26 and 28 are secured to the ring, as by affixing theirends to one side suface or face 24 with a mastic substance or solder 30,thus fixing the strands in cross relation on the ring to divide it intosegments. As is Well known, where cross strands are thus employed, meansare provided for positioning the intersection at substantially the focalplane of the sighting device whereby the intersection of the strandsbecomes the point of aim of the device. The strands 26 and 28 hereofeach include an inner core 32 of a selected material resistant to theaction of certain solvents, and an outer encasement 34 of a materialreadily attacked by said solvent. Examples of such material which arecurrently available and suitable for use herein are Wollaston wirewithan inner core 32 of platinum, and an encasement 34 of metal with a highsilver content; and wire of various metals coated with enamels orlacquers. Wollaston wire is known to possess the property of formingextremely small diameter reticle wires, which is achieved through removal of the outer encasement following affixation of the wire, and suchconstruction has heretofore been employed in aircraft bomb sights andsimilar high modification devices.

In the practice of the first form of the present invention a solvent,such as nitric acid, is employed to etch or dissolve the outerencasement 34 of the wire at one or more selected locations. Silver issubject to dissolution by said Solvent, while platinum is highlyresistant thereto. The solvent is applied at a selected location bymanual placement with an acid impervious probe 36 in small drops orquantities 38. In FIGURE 5, the solvent has been applied to a determinedcentral section of each of the strands 26 and 28, and has beenneutralized following a selected time of exposure, short of com letedissolution of the encasement, whereby the central sections have reduceddiameter encasements 40 tapering from the unaffected sections 42.Neutralization of the acid is accomplished through application of arinse, which may employ water as the rinse vehicle.

In FIGURE 7, the encasement 34 is fully removed at the central sectionby permitting a longer exposure of the encasement to the acid, wherebythe cross strands at substantially the center of the focal plane of thesighting device, are of minimum dimension. The encasement removalprocess leaves abrupt shoulders 46, tapering toward the center crosslines which also serve as an aid in sight alignment.

FIG'URES 8 through 10 show a series of reticles formed of a monometallicwire 50 employed as one of the cross strands, and conventional crosshair devices 52 arranged either substantially perpendicular or parallelthereto. The monometallic wire 50 is subject to solvent attackthroughout its full dimension or thickness. The configuration of thestrands of the wires 50 is a function of the exposure thereof to thesolvent and the application of the rinsein the same manner as applied 34 Alternative methods of reducing the diameter of the core toward thecentral portion of the strand to form strands at selected areas areavailable, as for example, said graduated taper. by concentratedabrasive application, mechanical expedi 2. The invention of claim 1,wherein: ents, and the like. the core is exposed at said centralportion.

What is claimed is: 5 3. The invention of claim 2, wherein: 1. A reticlefor a telescopic sighting device adapted at least two strands areprovided and comprise a pair for disposition at the focal plane of saiddevice, the reticle of crossed devices. compnsmg: References Cited anannular ring having opposing faces; a strand of sighting materialspanning said ring and 10 UNITED STATES PATENTS affixed to one of saidfaces; 848,757 4/1907 Lomb et a1 3350.5 X the strand being of graduatedtaper; 1,386,611 8/1921 Ely 33-505 X the strand including a discretecore with an encase- 2,180,184 11/1939 Weaver 3350.5 ment therearound;and 3,229,370 1/1966 Plisk et al. 3 350.5

said encasement being tapered in the direction of the 15 SAMUEL S MATTHEWS Primary Emminer

